Special Counsel Robert Mueller prevailed Tuesday when a judge turned down a request by former Trump campaign Chairman Paul Manafort to dismiss a federal indictment accusing him of money laundering and working as an unregistered foreign agent.

U.S. District Judge Amy Berman Jackson said Mueller didn't overstep his authority by charging Manafort with crimes unrelated to Russian election interference as defense lawyers claim. A dismissal would have been a blow to Mueller as he faces political attacks by President Donald Trump, congressional Republicans and conservative media. The ruling clears the way for a trial in September.

Jackson said the Manafort prosecution falls squarely within the mandate of Mueller, whose May 2017 appointment order directs him to investigate links or coordination between Russia and people associated with Trump's campaign. The charges against Manafort relate to his decade of work as a political consultant to Ukrainian politicians.

"Manafort was, at one time, not merely 'associated with' but the chairman of the presidential campaign and his work on behalf of the Russian-backed Ukrainian national party and connections to other Russian figures are matters of public record," Jackson wrote. "It was logical and appropriate for investigators tasked with the investigation of 'any links' between the Russian government and individuals associated with the campaign to direct their attention to him."

Beyond investigating links between Russia and Trump's campaign, Mueller is also charged with pursuing "any matter that arose or may arise directly" from his collusion probe. Jackson said that even if the Manafort case didn't arise from links to Russia, and instead was a matter that arose from that investigation, the indictment should stand.

Kevin Downing, Manafort's lawyer, didn't immediately respond to a request for comment on the ruling. Peter Carr, a spokesman for Mueller, declined to comment.

Manafort faces a separate trial set for July 10 in Alexandria, Virginia. The judge there is weighing a similar request to dismiss a tax- and bank-fraud case against him.